# Hydroxyprogesterone Caproate: veterinary dose and monograph

> Hydroxyprogesterone Caproate is a veterinary drug. Long-acting progestin — supports pregnancy by suppressing uterine contractions. Indications include habitual abortion; threatened abortion; uterine prolapse — follow-up. This monograph lists 3 reference doses for cattle, horses and goats, each with route, frequency and source, plus meat and milk withdrawal periods for food animals.

Source: https://vetmasterji.com/drugs/hydroxyprogesterone · Last reviewed: 2026-10-01

## At a glance

- **Drug class:** Veterinary drug
- **Also known as:** Progesyn, Proluton Depot
- **Species with doses:** Cattle, Horses and Goats
- **Routes:** IM
- **Last reviewed:** 1 October 2026

## Indications

- Habitual abortion
- Threatened abortion
- Uterine prolapse — follow-up

## Hydroxyprogesterone Caproate dose by species

Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.

### Cattle

*Hydroxyprogesterone Caproate doses for cattle*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Habitual / threatened abortion | 500–1000 mg per cow IM weekly (product literature) | IM | q7 days | — | Withdrawal NOT established — treat as extra-label |

- Habitual / threatened abortion: 500–1000 mg IM per cow weekly through critical gestation window. Dose per Indian product literature (Progesyn); hydroxyprogesterone caproate has no monograph in Papich 5e or Plumb’s.

### Horses

*Hydroxyprogesterone Caproate doses for horses*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Threatened abortion (mare) | 500–1500 mg per mare IM weekly (product literature) | IM | q7 days | — |

- Threatened abortion (mare): 500–1500 mg IM weekly under veterinary supervision.

### Goats

*Hydroxyprogesterone Caproate doses for goats*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Threatened abortion (doe) | 100–250 mg per doe IM weekly (product literature) | IM | q7 days | — | Withdrawal NOT established — treat as extra-label |

- Threatened abortion (doe): 100–250 mg IM weekly.

### Buffalo

No buffalo-specific doses are on file, so buffalo are dosed as cattle.

*Hydroxyprogesterone Caproate doses for buffalo*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Habitual / threatened abortion | 500–1000 mg per cow IM weekly (product literature) | IM | q7 days | — | Withdrawal NOT established — treat as extra-label |

- Habitual / threatened abortion: 500–1000 mg IM per cow weekly through critical gestation window. Dose per Indian product literature (Progesyn); hydroxyprogesterone caproate has no monograph in Papich 5e or Plumb’s.

## Contraindications

Hepatic disease. Pregnancy where progestin support is not indicated. Hypersensitivity.

## Species-specific warnings

> **Caution:** Cattle: Standard for habitual / threatened abortion at 500–1000 mg IM weekly. Confirm pregnancy + rule out infectious causes first.

> **Caution:** Horses: Mare threatened abortion: 500–1500 mg IM weekly under specialist supervision. Document luteal insufficiency before therapy.

> **Caution:** Goats: 100–250 mg IM weekly. Doe threatened abortion.

> **Caution:** Dogs: NOT commonly used in dogs — alternative progestins (medroxyprogesterone, altrenogest) are preferred.

> **Caution:** Cats: NOT commonly used in cats. Anti-fertility effect when used outside pregnancy.

## Adverse effects

- Local injection-site reaction
- Mammary stimulation
- Rare hepatic enzyme elevation on chronic use

## Drug interactions

- PGF2α (cloprostenol, dinoprost): ANTAGONISES progestin effect (causes luteolysis) — never co-administer in pregnancy maintenance
- Estrogens: opposing endocrine effects — clinically irrelevant in standard protocols
- Corticosteroids: theoretical antagonism — limited clinical impact
- CYP3A4 inhibitors (ketoconazole, erythromycin): may increase progestin levels
- CYP3A4 inducers (phenobarbital, rifampicin): may decrease levels

## Pregnancy and lactation

INTENDED for pregnancy maintenance — primary indication. Crosses placenta; high doses may masculinise female fetuses (rare at therapeutic IM doses). Excreted in milk in low amounts. Use only when clear indication (history of habitual abortion, documented luteal insufficiency). Avoid in non-pregnant females if pregnancy not desired (anti-fertility effect).

## Monitoring

- Pregnancy diagnosis by ultrasound / palpation BEFORE each weekly dose
- Injection site for sterile abscess / oily granuloma — rotate sites
- Serum progesterone (if available) as treatment endpoint
- Withdrawal periods (cattle): variable per jurisdiction; verify before slaughter / dairy use
- Discontinue at expected parturition (e.g. cattle ~270 d, mare ~330 d) — exogenous progestin can delay parturition

## Toxicity and overdose

Generally well tolerated at label doses. INJECTION-SITE reactions: sterile abscess, oily granuloma at the IM site (oily vehicle) — rotate sites. Hepatic enzyme elevation on chronic high-dose use. Mammary gland stimulation (rare swelling). Behavioural anoestrus during therapy. Persistent CL formation may delay return to oestrus after discontinuation. Cushingoid-like signs at high doses in dogs (rarely used).

Management: No specific antidote. Discontinue. Supportive: hepatic protection (SAMe) if hepatic enzymes elevated. Most overdoses well tolerated; return to oestrus may take 2–8 weeks after discontinuation due to depot effect. Injection-site abscess: drain if fluctuant, NSAID for pain.

## Clinical pearls

- Bovine habitual / threatened abortion: 500–1000 mg IM weekly through critical gestation window (typically months 2–7)
- Mare threatened abortion / luteal insufficiency: 500–1500 mg IM weekly under specialist supervision — verify progesterone deficiency first
- Goat / sheep doe threatened abortion: 100–250 mg IM weekly
- CONFIRM PREGNANCY before each dose — non-pregnant females will be anti-fertility
- DEEP IM ONLY (oily vehicle) — rotate sites every week to prevent sterile abscess
- Discontinue 1–2 weeks before expected parturition to allow normal labour
- Not effective for habitual abortion of infectious aetiology — investigate cause (Brucella, Leptospira, BVDV) before progestin therapy
- Long depot duration — return to cyclicity may take 2–8 weeks after final dose

## Mechanism of action

Long-acting synthetic progestin (17α-hydroxyprogesterone esterified with caproic acid → slow IM release over 7–14 days). Binds progesterone receptors in the myometrium and endometrium → suppresses uterine contractility, maintains endometrial decidualisation, and supports placental function. Reduces gonadotrophin (LH) release via negative feedback on the hypothalamus / pituitary → prevents oestrus cycling. Used to prevent abortion in mares / cows with low endogenous progesterone or repeated pregnancy losses.

## Formulations and products

- Progesyn 250 mg/mL injection (Intas, 3 mL ampoule)
- Progesyn (Intas (Neovet)) — 250 mg/mL, Oily IM injection
- Progress-Sure (Assure Biotech, Jagadhri (HR)) — Hydroxyprogesterone caproate 250 mg/mL - 750 mg per 3 mL ampoule, Oily injection - ampoule with 3 mL syringe and 21G needle
- A-Progen (Assure Biotech, Jagadhri (HR)) — Progesterone IP (micronised) 75 mg per 3 mL, Oily injection

## Storage

Oily injection (Progesyn): 15–25 °C, do NOT refrigerate (oil thickens). Protect from light. Multidose vial: 28 days after broaching, sterile technique mandatory.

## Before you use this dose

> **Caution:** Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.

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## Frequently asked questions

### What is the dose of Hydroxyprogesterone Caproate for cattle?

Reference doses for Hydroxyprogesterone Caproate in cattle: 500–1000 mg per cow IM weekly (product literature) IM q7 days (Habitual / threatened abortion). Confirm against the label and the patient before use.

### What is the dose of Hydroxyprogesterone Caproate for horses?

Reference doses for Hydroxyprogesterone Caproate in horses: 500–1500 mg per mare IM weekly (product literature) IM q7 days (Threatened abortion (mare)). Confirm against the label and the patient before use.

### What is the dose of Hydroxyprogesterone Caproate for goats?

Reference doses for Hydroxyprogesterone Caproate in goats: 100–250 mg per doe IM weekly (product literature) IM q7 days (Threatened abortion (doe)). Confirm against the label and the patient before use.

### What is the withdrawal period for Hydroxyprogesterone Caproate?

Cattle, IM (Habitual / threatened abortion): Withdrawal NOT established — treat as extra-label; Goats, IM (Threatened abortion (doe)): Withdrawal NOT established — treat as extra-label. Follow the product label and national regulations where they differ.

### When should Hydroxyprogesterone Caproate not be used?

Hepatic disease. Pregnancy where progestin support is not indicated. Hypersensitivity.

### What are the side effects of Hydroxyprogesterone Caproate in animals?

Local injection-site reaction; Mammary stimulation; Rare hepatic enzyme elevation on chronic use.

## Sources

- Intas Animal Health catalogue · Progesyn
- Plumb's Veterinary Drug Handbook
- Papich, Papich Handbook of Veterinary Drugs, 5th edition

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VetMasterJi is a clinical decision-support and education platform for veterinary professionals and students. It does not provide veterinary advice, diagnosis or treatment for specific animals. All drug doses, calculators and differentials are references that must be independently verified before clinical use; the attending registered veterinarian remains solely responsible for every clinical decision.